Cram up meaning

cram ​Definitions and Synonyms ​‌ · 1. transitive to put people or things into a space that is to...

cram的意思、解釋及翻譯：1. to force a lot of things into a small space: 2. to do many ... I was brought up ...

Your example lacks context. Where are the people crammed? Without knowing more, I would say that ...